package com.yrmjhtdjxh.punch.util;

import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.text.StrTokenizer;

import javax.servlet.http.HttpServletRequest;
import java.util.regex.Pattern;

public class GetIPAddressUtils {


//    public static  String getIpAddress(HttpServletRequest request) {
//
//        // nginx代理获取的真实用户ip
//        String ip = request.getHeader("X-Real-IP");
//        if (StringUtils.isBlank(ip) || "unknown".equalsIgnoreCase(ip)) {
//            ip = request.getHeader("X-Forwarded-For");
//        }
//        if (StringUtils.isBlank(ip) || "unknown".equalsIgnoreCase(ip)) {
//            ip = request.getHeader("Proxy-Client-IP");
//        }
//        if (StringUtils.isBlank(ip) || "unknown".equalsIgnoreCase(ip)) {
//            ip = request.getHeader("WL-Proxy-Client-IP");
//        }
//        if (StringUtils.isBlank(ip) || "unknown".equalsIgnoreCase(ip)) {
//            ip = request.getRemoteAddr();
//        }
//        /*
//          对于通过多个代理的情况， 第一个IP为客户端真实IP,多个IP按照','分割 "***.***.***.***".length() =
//          15
//         */
//        if (ip != null && ip.length() > 15) {
//            if (ip.indexOf(",") > 0) {
//                ip = ip.substring(0, ip.indexOf(","));
//            }
//        }
//        return ip;
//    }

    public static final String _255 = "(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)";
    public static final Pattern pattern = Pattern.compile("^(?:" + _255 + "\\.){3}" + _255 + "$");

    public static String longToIpV4(long longIp) {
        int octet3 = (int) ((longIp >> 24) % 256);
        int octet2 = (int) ((longIp >> 16) % 256);
        int octet1 = (int) ((longIp >> 8) % 256);
        int octet0 = (int) ((longIp) % 256);
        return octet3 + "." + octet2 + "." + octet1 + "." + octet0;
    }

    public static long ipV4ToLong(String ip) {
        String[] octets = ip.split("\\.");
        return (Long.parseLong(octets[0]) << 24) + (Integer.parseInt(octets[1]) << 16)
                + (Integer.parseInt(octets[2]) << 8) + Integer.parseInt(octets[3]);
    }

    public static boolean isIPv4Private(String ip) {
        long longIp = ipV4ToLong(ip);
        return (longIp >= ipV4ToLong("10.0.0.0") && longIp <= ipV4ToLong("10.255.255.255"))
                || (longIp >= ipV4ToLong("172.16.0.0") && longIp <= ipV4ToLong("172.31.255.255"))
                || longIp >= ipV4ToLong("192.168.0.0") && longIp <= ipV4ToLong("192.168.255.255");
    }

    public static boolean isIPv4Valid(String ip) {
        return pattern.matcher(ip).matches();
    }

    public static String getIpAddress(HttpServletRequest request) {
        String ip;
        boolean found = false;
        if ((ip = request.getHeader("x-forwarded-for")) != null) {
            StrTokenizer tokenizer = new StrTokenizer(ip, ",");
            while (tokenizer.hasNext()) {
                ip = tokenizer.nextToken().trim();
                if (isIPv4Valid(ip) && !isIPv4Private(ip)) {
                    found = true;
                    break;
                }
            }
        }
        if (!found) {
            ip = request.getRemoteAddr();
        }
        return ip;
    }

}
